title: Patient safety indicators for England from hospital administrative data: case-control analysis and comparison with US data.
abstract: OBJECTIVE
  To assess the feasibility of deriving patient safety indicators for England from routine hospital data and whether they can indicate adverse outcomes for patients.
  
  
  METHODS
  Nine patient safety indicators developed by the United States Agency for Healthcare Research and Quality (AHRQ) were derived using hospital episode statistics for England for 2003-4, 2004-5, and 2005-6. A case-control analysis was undertaken to compare length of stay and mortality between cases (patients experiencing the particular safety event measured by an indicator) and controls matched for age, sex, health resource group (standard groupings of clinically similar treatments that use similar levels of healthcare resource), main specialty, and trust. Comparisons were undertaken with US data.
  
  
  METHODS
  All NHS trusts in England.
  
  
  METHODS
  Inpatients in NHS trusts.
  
  
  RESULTS
  There was fair consistency in national rates for the nine indicators across three years. For all but one indicator, hospital stays were longer in cases than in matched controls (range 0.2-17.1 days, P<0.001). Mortality in cases was also higher than in controls (5.7-27.1%, P<0.001), except for the obstetric trauma indicators. Excess length of stay and mortality in cases was greatest for postoperative hip fracture and sepsis. England's rates were lower than US rates for these indicators. Increased length of stay in cases was generally greater in England than in the US. Excess mortality was also higher in England than in the US, except for the obstetric trauma indicators where there were few deaths in both countries. Differences between England and the US in excess length of stay and mortality were most marked for postoperative hip fracture.
  
  
  CONCLUSIONS
  Hospital administrative data provide a potentially useful low burden, low cost source of information on safety events. Indicators can be derived with English data and show that cases have poorer outcomes than matched controls. These data therefore have potential for monitoring safety events. Further validation, for example, of individual cases, is needed and levels of event recording need to improve. Differences between England and the US might reflect differences in the depth of event coding and in health systems and patterns of healthcare provision.
authors.affiliation: Healthcare Commission, London EC1Y 8TG. veena.raleigh@healthcarecommission.org.uk
authors.forename: Veena S
authors.initials: VS
authors.lastname: Raleigh
authors.forename: Jeremy
authors.initials: J
authors.lastname: Cooper
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Bremner
authors.forename: Sarah
authors.initials: S
authors.lastname: Scobie
mesh_terms: D016022:Case-Control Studies; D004739:England; D005240:Feasibility Studies; D006739:Hospital Administration / Q000706:statistics & numerical data; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D019984:Quality Indicators, Health Care; D017751:Safety Management; D013222:State Medicine / Q000592:standards*; D014481:United States